274 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



at about 15 per ton. In California tliey are especially valued in 

 strawberr}^ and vegetable culture, while in China their principal use 

 is as fertilizer for rice, tea plants, etc. In strawberry culture, from 

 300 to 400 i^ounds are commonly applied to each acre. It has also 

 been used in wheat-growing, being spread broadcast on the land after 

 the first plowing. 



AGRICULTURAL LIME FROM MOLLUSK SHELLS. 



The shells of oysters, clams, mussels, etc., have long been valued 

 for agricultural purposes. All along the Atlantic coast of the United 

 States, the extinct oyster beds, the old shell heaps, and even the living 

 oyster reefs have long been resorted to by the neighboring farmers as 

 a storehouse for top-dressing for their fields. In the Gulf States the 

 most luxuriant vegetation along the shore is upon the shell mounds 

 and marl deposits. Most of the material, however, is obtained from 

 the shucking establishments where moUusks are opened in large 

 quantities. Previous to the discovery of the limestone resources of 

 Pennsylvania and other States, large quantities of shells were burned 

 for lime; but at present their use for this purpose is confined largely 

 to localities where the shells are unusually abundant and cheap. 



An article in the Country Gentleinan, volume 7, page 155, refers to 

 the use of mussel shells for manure with especial reference to Essex 

 County, Mass., as follows: 



Thousands of cords of mussel shells are annually taken from tlie beds of the 

 streams bordering on the sea and used on cultivated groimd. I have repeatedly- 

 witnessed the value of this fertilizer in the growing of carrots and onions. The 

 very best crop of carrots I saw the last season, more than 34 tons to the acre, 

 had no other fertilizer applied to the land. For the last thirty years I have 

 known it applied to lands on which onions have been grown. Avith a product 

 varying from 300 to 600 bushels to the aci'e. It sells, delivered several miles 

 from Avhere it is dug, at $4 to $5 the cord. It is usually gathered in the winter 

 months, taken to the shore in scows or gondolas, and thence to the fields where 

 it is used. Sometimes it is laid in a pile of several cords together, and after it 

 has been exposed to the frosts of winter, distributed from 4 to 8 cords to the 

 acre. At other times it is laid oiit in heaps of a few bushels only, which remain 

 for a time exposed to the frost. 



According to Storer, "lime is not a fertilizer in itself, but is of 

 indirect value on land in unlocking the available potash, phosphorus, 

 and nitrogen in the soil." It also renders heavy, compact soils looser 

 in texture and tends to bind particles of loose, leachy soils. 



It is difficult to approximate the sum total of value which shells 

 confer on agriculture, owing to the extensive use of marl deposits. 

 Of refuse shells from shucking-houses and the like, the quantity used 

 in this country is doubtless upward of G0,000 tons annually. 



The prepared lime is generally preferred to the ground shells. 

 Analyses indicate that the organic matter contained in shells is well- 

 nigh free from nitrogen, and there is no evidence that it is of any use 

 as manure. It appears, therefore, that there is no need for the 

 expense of grinding the shells and of carting the useless constituents 



